Mode power spectrum for Laguerre-Gauss beams in Kolmogorov turbulence

We analyze the effects of atmospheric turbulence on the mode power spectrum of beams carrying orbital angular momentum represented by Laguerre-Gauss (LG) modes. For an input (0, m) LG mode, we calculate the power transferred to other modes (0, m') due to turbulence. The analysis is validated against split-step beam propagation simulations and shows agreement into the strong turbulence regime. These results have applications for the design and characterization of free-space laser communication systems. (C) 2022 Optica Publishing Group